require 'digest/sha1'

class User < ActiveRecord::Base
   # Virtual attribute for the unencrypted password
   attr_accessor :password  
  
   validates_presence_of     :login, :email
   validates_presence_of     :password,                   :if => :password_required?
   validates_presence_of     :password_confirmation,      :if => :password_required?
   validates_length_of       :password, :within => 4..40, :if => :password_required?
   validates_confirmation_of :password,                   :if => :password_required?
   validates_length_of       :login,    :within => 3..40
   validates_length_of       :email,    :within => 6..100
   validates_uniqueness_of   :login, :email, :case_sensitive => false
   validates_format_of       :email, :with => /(^([^@\s]+)@((?:[-_a-z0-9]+\.)+[a-z]{2,})$)|(^$)/i
  
   has_many :permissions
   has_many :matches
   has_many :roles, :through => :permissions
  
   before_save :encrypt_password
   before_create :make_activation_code
   
   # prevents a user from submitting a crafted form that bypasses activation
   # anything else you want your user to change should be added here.
   attr_accessible :login, :email, :password, :password_confirmation
  
   class ActivationCodeNotFound < StandardError; end
   class AlreadyActivated < StandardError
     attr_reader :user, :message;
     def initialize(user, message=nil)
       @message, @user = message, user
     end
   end
   
   # Finds the user with the corresponding activation code, activates their account and returns the user.
   #
   # Raises:
   #  +User::ActivationCodeNotFound+ if there is no user with the corresponding activation code
   #  +User::AlreadyActivated+ if the user with the corresponding activation code has already activated their account
   def self.find_and_activate!(activation_code)
     raise ArgumentError if activation_code.nil?
     user = find_by_activation_code(activation_code)
     raise ActivationCodeNotFound if !user
     raise AlreadyActivated.new(user) if user.active?
     user.send(:activate!)
     user
   end
  
   def active?
     # the presence of an activation date means they have activated
     !activated_at.nil?
   end
  
   # Returns true if the user has just been activated.
   def pending?
     @activated
   end
  
   # Authenticates a user by their login name and unencrypted password.  Returns the user or nil.
   # Updated 2/20/08
   def self.authenticate(login, password)    
     u = find :first, :conditions => ['login = ?', login] # need to get the salt
     u && u.authenticated?(password) ? u : nil  
   end
  
   # Encrypts some data with the salt.
   def self.encrypt(password, salt)
     Digest::SHA1.hexdigest("--#{salt}--#{password}--")
   end
  
   # Encrypts the password with the user salt
   def encrypt(password)
     self.class.encrypt(password, salt)
   end
  
   def authenticated?(password)
     crypted_password == encrypt(password)
   end
  
   def remember_token?
     remember_token_expires_at && Time.now.utc < remember_token_expires_at
   end
  
   # These create and unset the fields required for remembering users between browser closes
   def remember_me
     remember_me_for 2.weeks
   end
  
   def remember_me_for(time)
     remember_me_until time.from_now.utc
   end
  
   def remember_me_until(time)
     self.remember_token_expires_at = time
     self.remember_token            = encrypt("#{email}--#{remember_token_expires_at}")
     save(false)
   end
  
   def forget_me
     self.remember_token_expires_at = nil
     self.remember_token            = nil
     save(false)
   end
   
   def forgot_password
     @forgotten_password = true
     self.make_password_reset_code
   end
  
   def reset_password
     # First update the password_reset_code before setting the
     # reset_password flag to avoid duplicate email notifications.
     update_attribute(:password_reset_code, nil)
     @reset_password = true
   end  
  
   #used in user_observer
   def recently_forgot_password?
     @forgotten_password
   end
  
   def recently_reset_password?
     @reset_password
   end
   
   def self.find_for_forget(email)
     find :first, :conditions => ['email = ? and activated_at IS NOT NULL', email]
   end
   
   def has_role?(rolename)
     self.roles.find_by_rolename(rolename) ? true : false
   end
  
  
   protected
   
   # before filter
   def encrypt_password
     return if password.blank?
     self.salt = Digest::SHA1.hexdigest("--#{Time.now.to_s}--#{login}--") if new_record?
     self.crypted_password = encrypt(password)
   end
       
   def password_required?
     crypted_password.blank? || !password.blank?
   end
     
   def make_activation_code
     self.activation_code = Digest::SHA1.hexdigest( Time.now.to_s.split(//).sort_by {rand}.join )
   end
  
   def make_password_reset_code
     self.password_reset_code = Digest::SHA1.hexdigest( Time.now.to_s.split(//).sort_by {rand}.join )
   end
  
   private
   
   def activate!
     @activated = true
     self.update_attribute(:activated_at, Time.now.utc)
   end
end
